In his new book, "The Birth of the Pill," Eig discusses the story of how four people introduced a drug that changed women's rights forever.

A. I didn’t really know anything about the story. I knew that the birth control pill was this huge game changer, and it completely turned the world on its head in a lot of ways. And it just seemed amazing to me that anyone could invent the birth control pill—the pill is all about women’s power, and in the 1950’s the men had all the power.

I became very curious about this [idea]. It also struck me strange that the names of the inventors weren’t well known and so when I first looked into it, I was amazed by all of the people [involved] who had to do all incredible things just to get these things tested, not to mention approved. So when I realized that it was a story of these four outsiders, these underdogs, that’s really when I fell in love with the story and felt it was an important one to tell.

What were the founders up against at the time?

The hurdles were huge. Just remember, birth control was illegal in 30 states and the federal government had laws stating that you couldn’t even distribute information about birth control. So women had a very hard time getting access to any type of reliable contraception. They had to get help from men and help from doctors, and doctors were men. So if you were a single woman, forget about it – a lot of clinics required you to show proof that you were married or be able to show a receipt for your wedding dress.

It was just a very different world that we lived in. Women had very little control of their own reproductive lives, their own body. They couldn’t even complain to the police if their husbands raped them—marital rape was not a crime. Women had a huge challenge from not being able to control their bodies. As a result, they couldn’t go to college, they couldn’t have professional careers, their health suffered, and children were being born into dire circumstances. The world was very, very different before the pill.

The impact could be seen almost overnight. Within a couple of years you started to see birth rates dropping, you saw women started waiting longer to get pregnant. The average woman became a mother at age 21 in 1950, and by the 1960s that went up to 25. In the 1950’s the average mother had 3.7 children—this number went down to less than 2.

You also started seeing people having more sex outside of marriage. College life became a lot more fun, since there was a lot more sex on college campuses. All this happened really happened instantly, within months or years of the invention of the pill.

So let’s talk about the inventors. How did activist Margaret Sanger get involved?

Sanger worked in tenements and very early on saw suffering from unsafe abortions, women who couldn’t afford to take care of their 8 or 9 children, having their bodies worn out. She wanted to help these women. She also felt that sex was great and wanted women to be able to enjoy it and if you were a poor woman without access to any kind of contraception, there was no way you could enjoy having sex, since sex meant having a baby.

So she made sex her crusade. She founded Planned Parenthood and for 34 years while she opened birth control clinics, she went around saying, “What we really need is a pill – something magical that will allow women to turn on and off their reproductive system so they could stop having babies and then have them again whenever they were ready.”

That was her fantasy. She could never find anybody who would work on it because it sounded crazy, so she was in early seventies by the time she met biologist Gregory Pincus. She’d had heart attacks and was in pretty bad shape, but she was still going around saying, “I wish I could find a scientist who would agree to help make the birth control pill, I really think it’s the answer.” All the scientists told her she was crazy until she met Pincus, who’d been fired from Harvard and was running his own foundation out of a converted garage. That’s where the story really begins.

So why was Gregory Pincus scorned from the scientific community?

Pincus was experimenting with in vitro fertilization back in the 1930s and that scared people. He also liked to brag about it by saying that science was going to take over the reproductive process for making life on the planet. That idea really freaked people out. Harvard cut ties with him and he couldn’t find work anywhere else. As a result of that he was free to take chances that other scientists would never take, so he wasn’t worried about the controversy working with Sanger might bring—he had nothing to lose.

Women had very little control of their own reproductive lives, their own body...As a result, they couldn’t go to college, they couldn’t have professional careers, their health suffered, and children were being born into dire circumstances. The world was very, very different before the pill.

What was the exact science behind the development of the pill?

In [Pincus’] mind it was so simple that he thought it was beautiful. He told Sanger that woman’s bodies already had the tool it needs for contraception—it’s [a hormone] called progesterone. When a woman is pregnant, the body produces progesterone and that sends a message not to make more babies. So if he gives the women progesterone, her body will think it’s pregnant and she won’t release eggs.

He started experimenting immediately with lab animals and found that his idea worked. And then the next step obviously was to start working with women. But trying that became a little trickier because at the time birth control was illegal, so how was he going to find the women who’d be willing to participate in the studies? That’s where again where the story becomes really fascinating and complicated.

So this is where John Rock comes into the story. How did he help?

So Pincus was not a doctor, he was a scientist. He recruited a Catholic gynecologist named John Rock who was one of the most respected gynecologists in the country at the time, working at Harvard. Rock agreed to let Pincus use some of his patients who were coming to him for issues with infertility. So the very first people in this country who received birth control pills were women who were trying to get pregnant. So Rock and Pincus gave them contraceptives and said, “This is going to really make you infertile for awhile and maybe when you’re done you might have a hormonal rebound that will help your reproductive system.” Now [that idea] sounds crazy but it’s brilliant because it allowed them to test their pill and they found that in some cases women are able to get pregnant after they stopped taking hormones so it began to look like it was safe. So John Rock, who was Catholic and yet was willing to do this experiment, was able to give the research legitimacy and a respectable [public] face.

How did Rock measure up against Pincus and Sanger in the public eye? They all seem to have been thought of differently in terms of public opinion.

Everybody knew Pincus and Sanger were radicals, but Rock allowed the project to have some credibility. And he tried to sell the idea to the Catholic church—of course the Church didn’t go for it, but the fact that he was able to make this argument bought them some time to continue their work. And they moved quickly enough that they were able to get away with it and get the pill out there to women before the opposition could really do anything about it.

Since it’s introduction, what has changed with regards to the science behind the pill?

Well, back then the doses were much too high. They were just so worried about making sure that it was 100% effective, they were giving women 10 milligrams of progesterone and that was causing all kinds of side effects. They now realize that you can get by with a mere fraction of that. However, the basic science of the pill is still the same. Progesterone is still at the heart of many of the most effective birth control products on the market. The fact that Pincus saw that Progesterone was the answer was really brilliant, and his work is still having a huge impact today.

What was the most surprising thing you discovered while writing the book?

The most surprising thing was that the pill was actually approved by the FDA. It was crazy. They only tested it on 132 women for six months and the FDA gave approval. That would never happen today. If it had been even a couple years later even, it probably would not have been approved because the FDA’s standards got a lot tougher. So what I loved about this story was just how unlikely it all seemed to me—the fact that they pulled this off is the most shocking thing of all.

So what could we learn from some of the founder’s struggles?

I think that the main thing is that they took some chances and they did things that were unethical at times because they believed in the big picture to get this out. You know, women weren’t informed about what they were taking women in the experiments did not have to provide consent. They definitely cut some corners. But they felt like it was important because they had to make some sacrifices and I think there’s a lesson there that to make big, big bold changes, you have to make bold actions.

What do you think some of these characters would say about the women’s rights issues going on today?

I think it’s clear that there’s still controversy about the pill even though it’s been pretty well established that birth control saves women’s lives, babies lives, it’s good for public health, it’s been good for the economy and it’s allowed women greater equality.

But the fact that we’re still even arguing about it really speaks to how sexist we still are [in this country] and that people are still uncomfortable with the idea that women should be allowed to enjoy sex. It’s a bizarre backlash and I think the inventors of the pill would be stunned that we’re still fighting about it.

Jonathan Eig

Jonathan Eig is an acclaimed journalist and author. A former staff writer and contributing writer for the Wall Street Journal, Mr. Eig has written for numerous publications including the New York Times, Esquire, and The New Republic. His most recent book, released in October 2014 and entitled The Birth of The Pill: How Four Crusaders Reinvented Sex and Launched a Revolution, shares the remarkable story of how 4 incredible people—women’s rights activist Margaret Sanger, biologist Gregory Pincus, gynecologist John Rock, and philanthropist Katharine McCormick—banded together in the face of immeasurable social stigma to develop and introduce the birth control pill, a drug that changed women’s rights in the United States forever.